Hey Dave,
We've always used cachepath. Well, we're actually using the Ivy API
from Java code, but the idea is the same. It's never given us any real
problems, although when porting the code to the beta API (with the
separate artifact and resolution resolvers) we had to re-work it a
bit. We use retrieve to build copies of our application that we can
distribute, but for development and QA we only use artifacts directly
from the cache.
Cheers,
Colin